412 TRANSACTIONS OF THE WAGNER FREE 



pointed at the periphery of the whorl. Type : T. politnm Adams. This 

 group has two sections beside the typical one — Pseudorotella Fischer (1857), 

 in which the shell is small, the umbilicus closed and the aperture rounded 

 instead of drawn out, and Calceolina A. Adams (1863), in which the aperture 

 is drawn out, but not pointed at the periphery. Parkeria Gabb (1875) and 

 Megatyloma Cossmann (i 888) are synonyms of Pseudorotella. There remain 

 still a number of species in which the young stages of Teinostovia are per- 

 petuated, and which show generally an angle or ridge extending from the 

 pillar into the umbilicus spirally, and which sometimes is produced into a 

 thin broad keel, which might be taken for the umbilical wall, but really 

 overshadows the perforation of the axis and nearly closes it. Others have 

 the keel obscure, but the angle at the pillar compressed, as if it had been 

 pressed while soft somewhat away from the aperture. The surface may be 

 smooth or sculptured, the spire well-marked or involved in the last whorl, the 

 umbilicus usually marked by an opaque or callous area about it, though this 

 area may be concave, or not raised above the general surface. These shells 

 are obviously closely related to the others, and were named by Conrad in 1865 

 (Am. Journ. Conch., p. 30) Solariorbis. Delpldmda dcpressa I. Lea, his first 

 .species, may be regarded as the type. 5. ^f//rt, another species which follows, 

 is only a list-name; S. lincatiis (Lea) Conrad is a Solariella, and the other 

 example cited, 5. nitens Lea, is a peculiar species of Calliostonia. 



Among exotic species which may be referred to Solariorbis are Teinostoma 

 liosdenacense Cossmann and Rotella lunbiUcaris Deshayes. The group, in 

 short, comprises Ethalia of H. and A. Adams (ex parte). Carpenter, and my 

 Blake Report, but not the restricted original Ethalia oi K. Adams. Leiicorhyn- 

 chia Crosse (1867) is a Solarioi bis in which the umbilical keel, in the adult, is 

 so extended as to pass beyond the umbilicus, under the base of the shell, but 

 without closing it. The type is a recent species from New Caledonia. 



Dillwynella was described by me as a subgenus of Teinostoma, but, after 

 much consideration, I have concluded that it is entitled to generic rank. It 

 differs from the group represented by Teinostoma and Umbonium in possessing 

 an epidermis, and may perhaps turn out to have quite different relations when 

 the soft parts are known. Both these groups go back to the mid-Eocene in 

 America, and are represented in the existing fauna. 



In the preceding part of this paper, when the name Ethalia is used, as it 

 is in a few places, the reader will understand that the group here termed 

 Solariorbis is meant, and not Ethalia as now restricted to such forms as E. 

 guaniensis. 



Section Pseudorotella Fischer. 



This section is represented in the Claibornian by T. subrotundnm Meyer 

 and T. angulare Meyer; in the Jacksonian by T. VerrUlii Meyer. In the Older 

 Miocene we have T. chipolamim Dall ; in the Chesapeake Miocene T. nanum, 



